No more debates on climate science, over to leaders

(GLAND, Switzerland) – Today in Copenhagen, the Intergovernmental Panel on Climate Change released the final volume of its Fifth Assessment Report (AR5). The report represents seven years of work by more than a thousand scientists globally from 160 countries.

The world’s best climate scientists have given us a solid, thorough and conservative measuring stick for the global effort on climate change. This report has been approved by all 195 IPCC member governments as well as scientists. It represents an extremely broad and global scientific consensus on climate change.

It tells us that climate change is already affecting people and nature everywhere. Ocean acidification, sea level rise, extreme heat events, and profound changes in the Arctic show that climate change is already a fact. It tells us that we are the cause, and that our addiction to fossil fuels is the overwhelming source of the pollution that is changing our climate.

But while the report details the dire effects of an unstable climate, it also spells out a clear path to a cleaner, safer future. Its key findings are:

1) The world can afford to fight climate change. This will neither cripple economies nor stop development – to the contrary. What is clear is that inaction will be much more costly, even when considering conservative estimates.

2) It is not too late to avoid catastrophic climate change. Rapid, decisive action to get out of fossil fuels in particular can keep global temperature increases under 2º Celsius, which is the threshold indicated by science to avoid dangerous climate change, and agreed by governments.

3) There is a carbon budget – a limit on how much we can emit - and we have already used most of it. Globally, emissions must go down quickly, with emissions peaking this decade and going to zero mid-century if we want to avoid catastrophic climate change. Governments, businesses and indeed all of us must move beyond small steps, and move into phasing out fossil fuels completely.

4) Adaptation to climate change is critical, but there are sharp limits to it. Without immediate action on emissions and limiting impacts, adaptation will not be sufficient to protect lives, livelihoods and the natural world on which people depend.

5) Whether we act to cut emissions and adapt raises issues of equity, justice and fairness. If we fail to act, we jeopardise efforts to reduce poverty and endanger food, water and livelihoods for many of the world’s poor. We also leave today’s youth and future generations with a nearly insurmountable challenge.

In New York in September, people from all parts of society marched to demand action. Faith leaders, business, trade unions, students, grassroots organisations, civil society groups and individual citizens have called on governments to act swiftly and with ambition. Now, it is their turn – to use their broad mandate, provide the billions needed for this transition, and agree on the way forward for a global climate deal in Lima.